1. Field of the Invention
This invention relates to a device to pressurize cement when implanting an acetabular cup and to the device, when provided with an acetabular cup, and to a combination of the device and cup with an inserter. The device is also useful for appropriately positioning acetabular cups or trial cups in a desired anatomical position.
2. Description of the Prior Art
In acetabular reconstruction, a replacement component in the form of an acetabular cup can be fixed to the patient by the use of bone cement. For cemented acetabular constructions commonly using polymethyl methacrylate as the cement, the pressurization of the cement at the time of surgery is critical to successful fixation. The time available to the surgeon to achieve the necessary pressurization once the cement has been introduced into the acetabulum and the positioning of the component is relatively short.
It is therefore important for the surgeon to be able to establish the exact position of the cup before it is introduced into the acetabulum of a patient which has been reamed out to receive it. The present invention is intended to provide a device which will improve the cement fixation and the alignment of the cup in the acetabulum. Cement sealing devices for acetabular cups are known in the prior art and are shown in U.S. Pat. Nos. 4,324,000, 4,327,449 (which both have flanges), 5,501,687 and 5,507,748. With known acetabular cups having outwardly extending flanges, there is a risk of abrading material from the face and edge of the flange, which may be plastic, thus causing abrasions when in contact with bone cement.